Sorry, I ignored the second part of your question :-) Yews respond very well to hard pruning....very likely better than just about any other kind of shrub and certainly better than any other conifer. Can be cut back to just a short stump and will regenerate well.

With normal coloration noted.

As did I ignore the second part!!!

And here, so far, almost surprisingly, Gardengal and I are in total agreement. The yews can tolerate about any degree of pruning. I would suggest you prune harder/tighter than you think you need so that all of the growth that returns, while it is properly shaped, can remain with a loose somewhat fluffy look (as opposed to a tightly and regularly sheared look.) If by the end of the summer the new growth has outgrown its allotted space, don't shear again then. Wait until end of winter/early spring but cut even tighter/harder that you did in the previous year.

Thank you both! I’m excited to get these things under control. :)

BTW, when you conceive the forms, hopefully they will be in concert with the stand rules of proper pruning, of which the number one rule is do not undercut the lower portion of the shrub. It's sides should slope at least slightly outward as they travel downward. Many people just follow the shape that is there, trimming off a uniform layer from everywhere. Where there is nothing at the bottom, all it to grow instead of trimming something off. Try to make the collection of shrubs simpler. Either allow them to meld into single masses, or allow masses to coordinate in some way with the architectural elements (windows, walls). Make sure tops of shrubs are level and uniform with one another.

Something like this, @Yardvaark? Maybe less of an angle on the side and a little shorter but hard to draw on a phone. :) The center one below the window has always been super small and doesn’t seem to be growing much. There’s a large maple in the yard that may have some root competition or it may have just been planted years later. They’ve been there for at least 20 years and I’ve only been in the house for 5 years.

Your trim line is exactly at the bottom of the window, which gives you no room for growth and then leaving growth alone for the rest of the summer. Given the disparity of two side-by-side shrubs, which both belong to the same window or same house wall, I'd kill two birds with one stone and bring the larger shrub to the smaller shrub's size for some instant uniformity, though it probably won't last since the lower shrub won't bounce back with as much new growth.

Whether you trim with crisp, sharp corners and straight, sloped sides, OR, you trim with rounded shoulders and sloped sides, is a style choice and is purely up to you. They are both correct. I usually prefer the latter, but I like the former, too, when other people do it.

Follow a siding board edge as you trim the tops, since they are level.

Yep, planning on cutting a little shorter, couldn’t get my finger to draw the line in the right place. :)

Thanks for all the advice! I’ll try to post pictures once I’m done and have my new mulch down.

Hopefully these fill in quickly because it’s looking pretty scary here! The one that we had to make the shortest (and it still is slightly taller than the small one) was completely empty in the inside. All of the branches point outward. Are we talking months or years till this fills in? 😬😣

It will only be weeks. In a couple of months it should be pretty decent. I mad e pic but guess I forgot to upload it.